MP3212 MPS, MP3212 Datasheet - Page 12

• Manufacturer Part Number: MP3212
• Description: 1.3a, 1mhz Step-up Regulator With Integrated Input Disconnect Switch
• Manufacturer: MPS

transient and startup conditions. Calculate the
required inductance value by the equation:
Where I
the peak-to-peak inductor ripple current, and η is
efficiency.
Selecting the Diode
The output rectifier diode supplies current to output
when the internal MOSFET is off. To reduce losses
due to diode forward voltage and recovery time,
use a Schottky diode with the MP3212. The diode
should be rated for a reverse voltage greater than
the output voltage used. The average current
rating must be greater than the maximum load
current
must be greater than the peak inductor current.
MP3212 Rev. 0.9
3/21/2008
LOAD(MAX)
expected, and the peak current rating
I
IN
∆
(
MAX
I
MP3212–1.3A, 1MHz, STEP-UP REGULATOR WITH INTEGRATED INPUT DISCONNECT SWITHCH
L
=
is the maximum load current, ∆I is
=
(
)
30
V
=
V
IN
%
V
OUT
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
×
OUT
−
(V
50
×
OUT
f
V
×
SW
%
IN
I
LOAD
)
-
×
I
×
IN
V
η
∆
IN
(
MAX
I
(
MAX
)
)
)
© 2011 MPS. All Rights Reserved.
www.MonolithicPower.com
Layout Consideration
High frequency switching regulators require very
careful layout for stable operation and low noise. All
components must be placed as close to the IC as
possible. Keep the path between the SW pin,
output diode, output capacitor and GND pin
extremely short for minimal noise and ringing. The
input capacitor must be placed close to the IN pin
for best decoupling. All feedback components must
be kept close to the FB pin to prevent noise
injection on the FB pin trace. The ground return of
the input and output capacitors should be tied close
to the GND pin. See the MP3212 demo board
layout for reference
12